Rare Earth/Transition Metal Oxides For Syngas Cleanup,
2014
Louisiana State University and Agricultural and Mechanical College
Rare Earth/Transition Metal Oxides For Syngas Cleanup, Rui Li
LSU Doctoral Dissertations
Syngas from gasification of biomass or biomass and coal is a potential source of renewable energy. However, byproducts such as H2S and tars must be removed before further utilization or processing of syngas. Rare earth oxides (REOs, e.g., Ce/LaOx (1.7< x <2)) mixed with transition metals (e.g., Mn, Fe) were synthesized by various methods, and in some cases supported on a thermally stable alumina. Both desulfurization and tar reforming experiments were conducted at high temperatures under similar conditions with synthetic effluents in order to achieve better heat integration and higher yield to desired products CO and H2. The sulfur capacities at temperatures from 900-1025 K with air regeneration were measured for repeat cycles until a stable, reversible capacity was obtained. The oxidized and sulfided (reduced) sorbents were characterized by XRD, XANES, XAFS, TPR and BET. Density functional theory calculations were used to aid in interpreting characterization data and in explaining the enhanced S adsorption capacities. The results showed that mixed REOs, such as Ce/Tb, and Ce/La synthesized by a templated sol-gel approach do not have high sulfur capacities. The presence of either CO2 or H2O inhibits the adsorption of H2S. However, addition of Mn to REOs effectively increased the sulfur capacity, and Mn-REO sorbents are regenerable even in the presence of air, although there is some sulfate formation. The formation of elemental sulfur during regeneration could be related to the oxygen vacancies promoted by doping Mn into the ceria lattice. DFT calculations suggested doping Mn into CeO2 decreased the vacancy formation energies and lowered the H2S adsorption energy. In contrast, for MnO-doped REOs supported on ã-Al2O3, although their surface areas remained high after multi-cycle usage, the probable formation of MnAl2O4 as observed by XANES reduces the sulfur capacities. Reforming experiments were carried out using synthetic syngas mixtures with C10H8 as a tar model compound, both with and without H2S. The results showed that CO2 and H2O inhibit the reforming activities to some extent. Fe- or Mn-doped supported REOs are promising tar cleanup catalysts. They exhibited higher sulfur tolerance, less coking, and less methanation than typical Ni-based high temperature reforming catalysts. This behavior is in part attributed to enhanced generation of oxygen vacancies in the doped REOs.
Effects Of Different Preparation Methods On Structure And Catalytic Behavior Of Iron-Based Catalyst Via Fischer Trospch Synthesis Of Biomass-Derived Syngas,
2014
Louisiana State University and Agricultural and Mechanical College
Effects Of Different Preparation Methods On Structure And Catalytic Behavior Of Iron-Based Catalyst Via Fischer Trospch Synthesis Of Biomass-Derived Syngas, Khietlethanh Mai
LSU Master's Theses
Lignocellulosic biomass is a promising feedstock for producing liquid fuels via synthetic gas (syngas) and Fischer Tropsch Synthesis (FTS). Syngas produced from biomass has low H2/CO ratio (~0.7/1) and high concentration of CO2. In order to produce liquid hydrocarbons from this syngas, a catalyst must be used to increase the H2/CO ratio to 2 or higher. This catalyst must also have reasonable reverse water-gas-shift (R-WGS) activity in a CO2 rich environment. In this study, two 100Fe/4Cu/4K/6Zn were prepared using coprecipitation (Cat_C) and impregnation (Cat_I) methods. The effects of these preparation methods on the catalyst structure and FTS performance in biomass …
Controllable Synthesis Of Dispersed Spherical Fe3O4 Nanoparticles As Lithium-Inserted Materials,
2013
Engineering Research Center of Materials and Technology for Electrochemical Energy Storage (Ministry of Education), School of Chemistry and Environment, South China Normal University, Guangzhou 510006, China;
Controllable Synthesis Of Dispersed Spherical Fe3O4 Nanoparticles As Lithium-Inserted Materials, Hong-Li Zou, Wei-Shan Li
Journal of Electrochemistry
Dispersed spherical Fe3O4 nanoparticles were synthesized by a hydrothermal method. The influences of odecyl trimethyl ammonium bromide (DTAB) concentration on the morphology and particle size of the as-prepared Fe3O4 were studied. Electrochemical performance of the as-prepared sample as anode materials of lithium ion battery was investigated. It is found that the as-prepared sample exhibits superior rate performance and cycle performance. The nano-sized materials provide structural stability and favor the transfer of lithium ions.
Synthesis And Electrochemical Performance Of Nano Licopo4 By Polyol Method,
2013
School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
Synthesis And Electrochemical Performance Of Nano Licopo4 By Polyol Method, Fei Wang, Yang Jun
Journal of Electrochemistry
High potential LiCoPO4 cathode material was synthesized by polyol method. Carbon layer of ca. 3 nm thick was coated on the LiCoPO4 surfaces by chemical vapor deposition from methylbenzene. Crystalline structure, morphology and electrochemical performance of the sample were studied by XRD, SEM, TEM, CV and galvanostatic charge/discharge curve. The synthesized material via polyol method showed a pure phase of LiCoPO4. The LiCoPO4/C electrode delivered a high discharge capacity of 132 mAh·g-1 and maintained 78% of the initial capacity after 50 cycles at 0.1C rate. The two-step extraction/insertion behavior of Li+ in …
Aqueous Solution-Evaporation Route Synthesis And Phase Structural Research Of The Li-Rich Cathode Li1.23Ni0.09Co0.12Mn0.56O2 By In-Situ Xrd,
2013
Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Fujian Xiamen 361005;
Aqueous Solution-Evaporation Route Synthesis And Phase Structural Research Of The Li-Rich Cathode Li1.23Ni0.09Co0.12Mn0.56O2 By In-Situ Xrd, Chong-Heng Shen, Shou-Yu Shen, Zhou Lin, Xiao-Mei Zheng, Hang Su, Ling Huang, Jun-Tao Li, Shi-Gang Sun
Journal of Electrochemistry
The Li-rich Li1.23Ni0.09Co0.12Mn0.56O2 material was synthesized via aqueous solution-evaporation route. The structure and morphology of the material were characterized by means of XRD and SEM. The results indicated that the single particle of the product was polygonal with the size of 330 nm and the structure was layered solid solution with a certain amount of Li2MnO3. Electrochemical tests showed that the first discharge capacity of the Li-rich layered material was 250.8 mAh·g-1 at 0.1C, the capacity retention was 86.5% after 40 cycles. Through in-situ XRD study …
Synthesis And Electrochemical Property Of Li2Fesio4/C Cathode Material By Solid State Method,
2013
School of Chemistry and Material Science, Guizhou Normal University, Guiyang 550001, Guizhou, China;
Synthesis And Electrochemical Property Of Li2Fesio4/C Cathode Material By Solid State Method, Jiao-Li Sun, Zhi-Jiao Chen, Yi-Xiao Li, Hu Cheng
Journal of Electrochemistry
Li2FeSiO4/C cathode material was synthesized using Li2SiO3 and FeC2O4 as raw materials by solid state method. The structure and morphology of the material were characterized by XRD and SEM. The electrochemical properties of the material were studied by constant-current cyclic testing. The results show that Li2FeSiO4/C has a good electrochemical performance. The first discharge capacity of Li2FeSiO4/C cathode material at 30oC reached 167 mAh∙g-1 when cycled at 10 mA∙g-1 between 1.5 and 4.8 V.
A Dynamic Optimization Framework With Model Predictive Control Elements For Long Term Planning Of Capacity Investments In A District Energy System,
2013
Brigham Young University - Provo
A Dynamic Optimization Framework With Model Predictive Control Elements For Long Term Planning Of Capacity Investments In A District Energy System, Jose Luis Mojica Velazquez
Theses and Dissertations
The capacity expansion of a district heating system is studied with the objective of evaluating the investment decision timing and type of capacity expansion. District energy is an energy generation system that provides energy, such as heat and electricity, generated at central locations and distributed to the surrounding area. The study develops an optimization framework to find the optimal investment schedule over a 30 year horizon with the options of investing in traditional heating sources (boilers) or a next-generation combined heat and power (CHP) plant that can provide heat and electricity. In district energy systems, the investment decision on the …
A Kinetic Study Of Aqueous Calcium Carbonate,
2013
Brigham Young University - Provo
A Kinetic Study Of Aqueous Calcium Carbonate, Derek Daniel Harris
Theses and Dissertations
Amorphous calcium carbonate (ACC) precipitation is modeled using particle nucleation, growth, and aggregation. The particles are tracked in terms of their radial size and particle density using direct quadrature method of moments (DQMOM). Four separate nucleation models are implemented and are compared to experimental data. In discord with a recent study, it is shown that classical nucleation, coupled with equilibrium chemistry, is in good agreement with experimental data. Novel nucleation mechanisms are presented which fit the experimental data with slightly greater accuracy. Using equilibrium chemistry it is shown that the equilibrium value of ACC is pKeq = 7.74 at 24C, …
Molecular Modeling Of Dna For A Mechanistic Understanding Of Hybridization,
2013
Brigham Young University - Provo
Molecular Modeling Of Dna For A Mechanistic Understanding Of Hybridization, Terry Jacob Schmitt
Theses and Dissertations
DNA microarrays are a potentially disruptive technology in the medical field, but their use in such settings is limited by poor reliability. Microarrays work on the principle of hybridization and can only be as reliable as this process is robust, yet little is known at the molecular level about how the surface affects the hybridization process. This work uses advanced molecular simulation techniques and an experimentally-parameterized coarse-grain model to determine the mechanism by which hybridization occurs on surfaces and to identify key factors that influence the accuracy of DNA microarrays. Comparing behavior in the bulk and on the surface showed, …
Microgrid Development Using A Grid Tie Inverter,
2013
Faculty of Engineering, Universitas Indonesia, Depok 16424, Indonesia
Microgrid Development Using A Grid Tie Inverter, Hartono Budi Santoso, Budiyanto Budiyanto
Makara Journal of Technology
The use of renewable energy sources (RES), especially photovoltaic (PV), to meet the demand of electrical energy has been getting a great deal of attention as an alternative solution to electrical energy deficit problems. RES are being applied in power systems in a variety of configurations including microgrid systems. One of the characteristics of a microgrid is capability to supplying power to grid when there is an excess power to supply local load. This research examines the chances of saving power consumption from grid using power converters grid tie inverter (GTI) in a microgrid configuration. The test is done by …
Surface Treatment Of Fly Ash For Improving The Tensile Strength Of Fly Ash/Unsaturated Polyester Composites,
2013
Department of Mechanical Engineering, Faculty of Engineering, University of Mataram, Mataram 83125, Indonesia
Surface Treatment Of Fly Ash For Improving The Tensile Strength Of Fly Ash/Unsaturated Polyester Composites, Sugiman Sugiman, Paryanto Dwi Setyawan
Makara Journal of Technology
The paper presents the surface treatment of fly ashes using acid and alkali solution on the tensile strength of the fly ash/unsaturated polyester (UP) composites. Sulfuric acid (H2SO4), hydrofluoric acid (HF) and sodium hydroxide (NaOH) solution with concentration of 0%, 5%, 10%, 15%, and 20% (by weight) were used for surface treatment of fly ashes. Generally, the tensile strength of the treated fly-ash/UP composites shows a significant increase compared to the untreated fly ash. Of all surface treatments studied, the optimum tensile strength was obtained at a concentration of 10%. At this concentration, at a fly ash content of 30% …
Recycling Roof Tile Waste Material For Wall Cover Tiles,
2013
Interior Design Department, Letters and Visual Arts Faculty, Sebelas Maret University, Surakarta 57126, Indonesia
Recycling Roof Tile Waste Material For Wall Cover Tiles, Ambar Mulyono, Silfia Mona Aryani, Joko Lulut
Makara Journal of Technology
Prior research on roof tile waste treatment has attempted to find the appropriate technology to reuse old roof tile waste by create wall cladding materials from it. Through exploration and experimentation, a treatment method has been discovered to transform the tile fragments into artificial stone that resembles the shape of coral. This baked clay artificial stone material is then processed as a decorative element for vertical surfaces that are not load-bearing, such as on the interior and exterior walls of a building. Before applying the fragments as wall tiles, several steps must be taken: 1) Blunting, which changes the look …
Synthesis Of Tungsten Oxide Nanowires Onto Ito Glass Using T-Cvd,
2013
Graduate Institute of Electro-Optical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan, R.O.C.
Synthesis Of Tungsten Oxide Nanowires Onto Ito Glass Using T-Cvd, Tomy Abuzairi, Bohr-Ran Huang, Tzu-Ching Lin
Makara Journal of Technology
Tungsten oxide is an n-type semiconductor with interesting physical and chemical properties that make it suitable for various technological applications. Tungsten oxide nanowires were synthesized not only at low temperature but also without the use of any catalysts. The tungsten oxide nanowires were synthesized at 550 °C with tungsten layers onto the ITO glass using thermal chemical vapor deposition (T-CVD). The SEM image shows that the tungsten oxide nanowires are effectively grown with the 200 nm tungsten film. The Raman spectra shoulder at ~690 cm-1 proves the synthesized of tungsten oxide nanowires.
Semiconductor Thermal Neutron Detector,
2013
Research Institute of Electronics, Shizuoka University, Hamamatsu, Shizuoka 432-8011, Japan
Semiconductor Thermal Neutron Detector, Toru Aoki, Aki Miyake, Takayuki Nakano, Akifumi Koike, Hisashi Morii, Hidenori Mimura
Makara Journal of Technology
The CdTe and GaN detector with a Gd converter have been developed and investigated as a neutron detector for neutron imaging. The fabricated Gd/CdTe detector with the 25 mm thick Gd was designed on the basis of simulation results of thermal neutron detection efficiency and spatial resolution. The Gd/CdTe detector shows the detection of neutron capture gamma ray emission in the 155Gd(n, g)156Gd, 157Gd(n, g)158Gd and 113Cd(n, g)114Cd reactions and characteristic X-ray emissions due to conversion-electrons generated inside the Gd film. The observed efficient thermal neutron detection with the Gd/CdTe detector shows its promise in neutron radiography application. Moreover, a …
Radiation Characteristics Of A Planar Strip Dipole Antenna And A Slot Dipole Antenna For Thz Applications,
2013
Antenna Propagation and Microwave Research Group (AMRG), Department of Electrical Engineering, Faculty of Engineering, Universitas Indonesia, Depok 16424, Indonesia
Radiation Characteristics Of A Planar Strip Dipole Antenna And A Slot Dipole Antenna For Thz Applications, Catur Apriono, Eko Tjipto Rahardjo
Makara Journal of Technology
The development of a THz system often requires a device that is used to radiate or detect THz waves. One way to fulfill this requirement is to use an antenna. Therefore, we need to consider the radiation characteristics of an antenna working in the THz region. In this paper, we present simulation study of two dipole antennas, i.e. a planar strip dipole antenna and a slot dipole antenna. The simulation results show that a planar strip dipole antenna has a better radiation efficiency (more than 95%) compared to the slot dipole. It also shows that an efficiency of more than …
The Effect Of Pressing Temperature And Time On The Quality Of Particle Board Made From Jatropha Fruit Hulls Treated In Acidic Condition,
2013
Major of Forestry, Faculty of Agriculture, North Sumatera University, Medan 20155, Indonesia
The Effect Of Pressing Temperature And Time On The Quality Of Particle Board Made From Jatropha Fruit Hulls Treated In Acidic Condition, Apri Heri Iswanto, Fauzi Febrianto, Yusuf Sudo Hadi, Surdiding Ruhendi, Dede Hermawan
Makara Journal of Technology
The high of pH of jatropha fruit hulls causes the negative properties of particleboard made from this material. Adjusting the particle acidity and pressing conditions (temperature and time) is among the technical modifications available to improve this particleboard’s properties. Particle acidity has been adjusted in a previous research project, and immersing the particles in acetic acid was found to be the best treatment in this preliminary research. In order to improve the particleboard’s properties, an experiment was conducted to determine the best pressing temperature and time. The objective of the research was to evaluate the influence of pressing temperature and …
Minimal Medium For Optimal Growth And Lipid Production Of The Microalgae Scenedesmus Dimorphus,
2013
Cleveland State University
Minimal Medium For Optimal Growth And Lipid Production Of The Microalgae Scenedesmus Dimorphus, Colin Welter, Jacob Schwenk, Bahar Kanani, John Van Blargan, Joanne M. Belovich
Chemical & Biomedical Engineering Faculty Publications
The culture of Scenedesmus dimorphus at the laboratory scale has often been in standard microalgae media, such as 3N-Basal Bold medium (3N-BB), which contains 15 different chemicals. Given the extremely tight profit margins of large-scale production of biofuel from microalgae, it is important to identify the minimally sufficient quantities of nutrients necessary to maximize lipid productivity. The individual and interactive effects of six groupings of the components of 3N-BB medium on growth rate, lipid content, and total biomass yield of S. dimorphus were determined. Trace metal and vitamin concentrations were reduced to 1/6 the level of 3N-BB medium without adversely …
Sulfonated Perfluorocyclobutyl (Pfcb) Aryl Ether Polymers: Synthesis, Reactivity, And Characterization For Polymer Electrolyte Applications,
2013
Clemson University
Sulfonated Perfluorocyclobutyl (Pfcb) Aryl Ether Polymers: Synthesis, Reactivity, And Characterization For Polymer Electrolyte Applications, Jiyoung Park
All Dissertations
Perfluorocyclobutyl (PFCB) aryl ether copolymers are excellent candidates for proton exchange membrane (PEM) component in PEM fuel cells. Sulfonated PFCB copolymer membranes exhibit not only high chemical/thermal/mechanical stability but also high proton conductivity. In this regard, PFCB aryl ether copolymers were synthesized via thermal step-growth [2 + 2] cyclopolymerization from aryl bis-(trifluorovinyl ether) (TFVE) monomers and oligomers. Experimental and computational studies confirmed that copolymerization of relatively electron-rich and electron-poor TFVE monomers gave selective-segmented copolymers in an one-pot polymerization. After sulfonation, the PFCB copolymers comprising hydrophilic and hydrophobic segments gave membranes with high proton conductivity. Cross-linked membranes of the sulfonated PFCB …
Structural Characterization Of Super-Acid Oligomerized Fatty Esters.,
2013
Pittsburg State University
Structural Characterization Of Super-Acid Oligomerized Fatty Esters., Esam Allehyani
Electronic Theses & Dissertations
Fatty acid methyl esters can be oligomerized with very strong acid catalysts - superacids such as tetrafluoroboric or triflic acid with formation of dimer and trimer fatty acids at much lower temperature, such as 80-90 °C, than what is used presently. Insight into the reaction of polymerization of fatty esters/ acids can be obtained by structural characterization. This would determine the properties of the oligomeric products and their ability to substitute currently used materials. It was presumed that dimer fatty, trimer fatty acid esters, and oligomeric fatty acid esters are produced by polymerization of fatty acid methyl esters by a …
Gas Composition Analysis Using Limited Production Data Eagle Ford Case Study,
2013
Louisiana State University
Gas Composition Analysis Using Limited Production Data Eagle Ford Case Study, Ryckur K. Shuttler
Honors Capstones
No abstract provided.
